Electric-light dimmer.



\ No. a5|,47s. Patented lune I2, I900.

F. E. woouronn. I

ELECTRIC LIGHT DIMMER.

(Application filed Sept. 26, 1898.)

(No Model.)

UNITED STATES PATENT OFFICE,

FRANK E. wooDFoRi), OF APPLETON, Wisconsin.

ELECTRIC-LIGHT DIMMEFi.

SPECIFICATION forming part of Letters P'ateht Ne. 651,473, dated June12, 1900.

Application filed September 26, 1898. Serial No. 691,956. (11'0 model.)

To all "whom it mag concern.-

Be it known that I, FRANK E. WOODFORD,

a citizen of the United States, residing at Appleton, in the county ofOutagamie and State of \Visconsin, have invented certain new and usefulImprovements in Electric-Light Dimmers or Regulators, of which thefollowing is a specification. My invention relates to that class ofelectric lights in which the brilliancy or intensity of the light isregulated by sliding contacts and rheostats.

My improvements are more especially adapted to incandescent lamps. Theirobject is to simplify the construction of the apparatus by reducing thenumber of its parts and to render the apparatus more easy of operation.These ends I attain by mounting the lamp directly upon, and thus causingit to move with, the support, to which a resistance-coil is alsoattached, and which thus moves simultaneously with the lamp, contactdevices being employed with circuit connections, whereby as the lamp andthe resistance-coil are moved a greater or less number of convolutionsof the coil are thrown into or out of the circuit to thus vary theintensity of the light.

The subject-matter deemed patentable is set forth in the claim. I

The accompanying drawing, which represents a view partly in elevationand partly in vertical central section through an apparatus embodying myimprovements, shows a tubular body having its lower end inserted in anon-conducting base B, such as wood.

This body is shown as consisting of two shells or tubes A O, of metal,such as brass or copper, one inside the other and each insulated fromthe other. Perforations P through these tubes, at top and bottom, permitair to circulate therethrough. The top of the lamp-body is closed by aninsulated cap N, having a central perforation through which alamp-support passes.

The lamp is shown as mounted on a support consisting of a tube D, ofsheet metal, such as brass, which extends down through the cap N intothe body of the lamp, being capable of moving endwise therein and beingguided in its movements by the hole in the cap N and by an uprightcentral standard or guide-pin O, secured in the base 13.

Aresistance-coil E of well-known construction and material, such as aGerman-silver wire coil, is mounted upon but insulated from thissupporting-tube D. The upper end of the coil E terminates in aconducting-wire E, which after making a few turns around the tube Denters it and extends upward to the lamp inside the tube, forming one ofits terminals. The other terminal likewise extends downward through thetube D and makes contact with the inner tube 0 through c011- tact-springG, mounted on an insulated ring H, of fiber or like material, carried bythe supporting-tube D.

Contact-springs L are secured at their lower ends in the base B andsuitably insulated. The upper ends of these springs are in contact withthe conducting-wire F above the resistance-coil E. These springs L arethus connected with one terminal of the lightingcircuit and the innertube 0 with the other.

The drawing shows the springs L in direct contact with the circuit-wireF. The lamp is consequently burning with full brilliancy. Raising thelamp causes the support D to rise correspondingly, lifting theresistance-coil E with it, and thus gradually increasing the resistanceof the circuit as it slides over the contact-springs L in a Way wellunderstood. The organization is such that, assuming the lamp to burnwith sixteen-candle power in its lowest position, the light may bereduced to a half-candle power when fully elevated.

It will be observed that when the lamp is lifted the resistance-coil isalso lifted, and the arrangement of the springs L is such that a greateror less number of the convolutions of the coil are included in thecircuit as the lamp is raised or lowered. I preferably employ twosprings L to prevent sparking, as when one spring does not make goodelectrical connection with the coil the other spring is apt to do so;but one spring may be employed, if desired, as the circuit can readilybe made through a single spring.

' I claim as my invention The combination of a non-conducting base, ametallic shell or casing secured thereto and rising therefrom, anincandescent electric lamp, a contact-spring bearing on theshell orcasing and connected to the other terminal of the filament, acontact-spring bearing on the coil and circuit-Wires connected to the10' casing and to the contact-spring which bears on the coil.

FRANK E. WOODFORD. WVitnesses:

A. J. SIMPICH, W. J. VAUGHN.

